你可以自费买medicare，几百元还是付得起的。

1.  自费买medicare

https://www.aarp.org/health/medicare-insurance/info-04-2011/medicare-eligibility.html

You just have to pay premium for medicare part A, B and D, while those with 40 points don't pay premium for medicare part A (but they still pay premium of part B and D).   

2.  As for social security, you don't need it if you have your own investment and savings. 

当然，如果你自己开一个公司然后付自己一定工资同时交payroll tax，说不定交了十年然后退休可能medicare／SS的benefit比你交的payroll tax还多。所以如果你想做功课这么做，也不是不值得。但是如果你不这么做，你也是活得下去的，没有必要为此失眠。